If TDs are to be seen as national politicians, then you should contact them on national issues, I know that you should also contact your local TD on national issues so the party can get an idea of where the issue is being raised, but usually the TD just says they'll pass it on to their issues spokesperson, so if you want a quicker response you can should email the spokesperson directly on your topic of interest as well.

shadow spokespeopleshadow spokespeople
There's less of clear showing of cabinet positions in Ireland, but I think I have most of them right,(actually i made this 6months ago and its probably in need of an update) if it open the spreadsheets and change em.